<!doctype html>
<html lang="zn-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title><script src="https://cdn.bootcss.com/jquery/3.2.1/jquery.min.js"></script>
</head>
<body>
    <p id="text">hello world<a>baidu</a></p>
    <button id="btn1">点击</button>
    <p><input type="text" id="txt" value="yingxionglianmeng"></p>
    <p><a id="aid" href="http://baidu.com"></a></p>
    <button id="btn2">点击2</button>
    <script src="js/demo1.js"></script>
</body>
</html>